ἀντιπταίω
From LSJ
θοῦ, Κύριε, φυλακὴν τῷ στόµατί µου καὶ θύραν περιοχῆς περὶ τὰ χείλη µου → set a guard over my mouth, Lord; keep watch over the door of my lips | set a guard, O Lord, over my mouth; keep watch over the door of my lips (Psalm 140:3, Septuagint version)
English (LSJ)
obstruct, stand in the way, πρός τι Onos.17.
Spanish (DGE)
obstaculizar, obstruir πρὸς τὸν ῥόμβον Onas.17.